1. Field of the Invention
The present invention relates to a self-diagnosis device for the printer by which a condition of functional devices provided in the printer is automatically diagnosed by a built-in microcomputer.
2. Description of the Related Art
A printer now used for printing the output from a host computer is provided with a built-in microcomputer for controlling the functions of the printer, but recent increases in the number of functions of the printer have led to a corresponding increase in the number of functional mechanisms provided for carrying out these functions, and thus, when a fault occurs in the printer, it is difficult to pinpoint the cause of the fault.
Accordingly, some current printers are provided with a self-diagnosis function by which, when a power supply is turned ON, each functional mechanism is pre-tested, and an error warning is displayed if a fault is detected by these tests.
In a conventional self-diagnosis device of a printer, however, even if a plurality of functional mechanisms are to be tested, when an error is detected in a pre-test, tests of the remaining functional mechanisms are not carried out. Namely, the self-diagnosis process is stopped and the self-diagnosis device outputs an error warning. Therefore, if more than one of the functional mechanisms in the printer has a fault, only one of these faulty mechanisms is detected by the single diagnosis process.
Accordingly, when a plurality of errors exist in the printer, the power supply must be turned ON again each time an error is to be found and corrected, which is time-wasting and cumbersome.